Schematic diagram of the new design for a device to generate high-frequency reference signals. A source (red) produces a stream of electrical pulses that are sent to a circuit that converts each incoming pulse into an outgoing SFQ pulse (purple). Each SFQ is routed to three stages of splitters (S, green), which make duplicate signals. Finally, the output is sent to an array of superconducting quantum interference devices (ST, light blue) which collects all the signals and combines them into an output large enough to be readily detected by electronic instruments. Everything inside the pale blue dotted line is cooled to four kelvin.
Researchers at the National Institute of Standards and Technology (NIST) have devised and demonstrated the output components of a novel, quantum-based, self-calibrating standard for testing components and instruments in next-gen telecommunications networks. With further development, the system may eventually provide reference signals for networks running at, and soon far above, the present 5G range that can reach 24 to 39 billion cycles per second (gigahertz, GHz). That’s more than 10 times faster than 4G.
At this time, there is no quantum-based reference standard. As a result, it is already extremely difficult to measure, characterize, and calibrate signals accurately at 5G speeds, detecting problems such as waveform distortion and synchronization errors in components and systems. Eventually, “high-band” networks will operate at frequencies up to 100 GHz and possibly beyond, posing a formidable measurement challenge.
Moreover, at higher frequencies targeted for urban areas, waveforms lose their strength over shorter distances, so the fastest signals will have to be boosted more often by larger numbers of precisely synchronized cell sites and repeaters, all without altering the timing and shape of the waveforms. Monitoring and maintaining the integrity of such networks will demand measure ..